[bk_mike]

Can someone that has done the brake bleeding procedure provide a little more insight into the ISTA bleed procedure? the instructions in ISTA aren't the best. I am using a motive power bleeder but I can't seem to get a firm pedal.

[Sylverlee]

Did you get air in the system? I’ve done it without ISTA and still got a firm pedal

[Surly73]

I've done the ISTA process a few times with a Motiv power bleeder. I didn't find the instructions unclear. The only thing I didn't follow from the instructions is that I do not push the brake pedal to the floor.

It's an old school practice, but I put a block of wood or a brick under the brake pedal to keep it in the normal operating range. The theory is that the portion of the master cylinder bore that does not normal get used is not polished smooth and may also contain barbs or other such things that damage the master cylinder piston seal therefore requiring a new master cylinder shortly after the bleeding process. No thanks. As the car gets older, I see the risks increasing with little reward, so I intend to keep doing it this way.

[spielnicht]

Did you manually bleed the system before following the ISTA procedure? That's a prerequisite.

As for the ISTA procedure itself, I honestly just followed the prompts and my mushy pedal got firm immediately following all 4 caliper installs. The loud noise and pulsating pedal can be intimidating during the procedure, but just keep a firm push on the pedal.

[bk_mike]

Thanks everyone for the replies. I swapped all 4 calipers, lines and removed the master cylinder reservoir to clean it so there is air everywhere. I used a motive power bleeder before i started and got solid fluid coming from all the lines.

I guess here is the question I should have asked... When ISTA says press the pedal for 5 seconds does that mean push it to the floor and count to five or push the pedal all the way down and up as many times as you can for five seconds?

[Surly73]

Originally Posted by bk_mike

Thanks everyone for the replies. I swapped all 4 calipers, lines and removed the master cylinder reservoir to clean it so there is air everywhere. I used a motive power bleeder before i started and got solid fluid coming from all the lines.

I guess here is the question I should have asked... When ISTA says press the pedal for 5 seconds does that mean push it to the floor and count to five or push the pedal all the way down and up as many times as you can for five seconds?

By my recollection, ISTA says push the pedal to the floor EVERY 5 seconds. No? Meaning repeatedly pressing and releasing at 5s intervals.

[Sylverlee]

Yup that’s what I did my other car. Up and down slowly and you’ll see the fluid coming out

[Blue Angel]

For what it's worth, I did the brakes on my F10 a year and a half ago and they felt very average. I gravity bled each calliper and got a few small air bubbles out, but the brake pedal was just OK, not great.

Fast forward a year and a half and the pedal feels fantastic. I'm not sure what has changed other than the pads being bedded properly, but I certainly have a totally decent feeling pedal now that reacts very quickly at the top of the travel and has a good progressive feel.

I guess all I am saying is, I even if your pedal doesn't feel fantastic right after the brake job try driving it for a few weeks and see if it improves. Unless of course the pedal is completely soft and the car is unsafe to drive.

[bk_mike]

FYI I ran through the procedure again and it feels good now. Thanks to everyone for the input.